﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace WebApplication1
{
    public partial class WebForm2 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                DropDownList1.Items.Add("新华社");
                DropDownList1.Items.Add("新华社2");
                DropDownList1.Items.Add("新华社3");
                Label4.Text = DateTime.Now.ToString();
            }
        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            string innerText = Content.InnerText;
            if (string.IsNullOrEmpty(innerText))
            {
                Label5.Text = "请输入新闻内容";
            }
            else
            {
                Label5.Text = $"此新闻来自{DropDownList1.SelectedValue}";
            }
        }

        protected void Button2_Click(object sender, EventArgs e)
        {
            Content.InnerText = null;
        }
    }
}